Oil pan isolation mounting and seal

ABSTRACT

Arrangements for sound deadening vibration isolation mounting of an engine oil pan on an associated frame or block are provided wherein special flange opening gripping or guiding resilient seals combine with flange recesses, rubber-metal isolators and shoulder bolts or the like to aid installation of the pan and mounting means on an engine.

FIELD

This invention relates to engine oil pans and mountings therefore and,more particularly, to sound deadening vibration isolating seals and oilpan mounting arrangements for engines

BACKGROUND

Various arrangements and means for mounting oil pans and othercomponents in sound deadening vibration isolation from the main frame orblock of an internal combustion engine are becoming well known in theart. Such arrangements are disclosed, for example, in my prior U.S. Pat.No. 4,394,853 issued July 26, 1983 and in U.S. Pat. No. 4,423,707 ofSihon and Ransom issued Jan. 3, 1984, both assigned to the assignee ofthe present invention.

INVENTION SUMMARY

The present invention provides additional mounting arrangements andmeans for vibration isolation mounting of an engine oil pan to the frameor block. Each arrangement includes the provision of a pan flange andassociated seal having aligned fastener openings guiding on sleeve-likecylindrical projection portions of the seal. Grommet-like retainers onthe projections or cooperation of the projections with seal engaged boltbodies act to retain the seal against the oil pan flange duringinstallation of the pan on an engine frame or block.

These and other features and advantages of the invention will be morefully understood from the following description of selected embodimentstaken together with the accompanying drawings.

DRAWINGS

In the drawings:

FIG. 1 is a side view of the lower portion of an engine assembly showinga frame carried oil pan with a vibration isolation mounting inaccordance with the invention;

FIG. 2 is a fragmentary cross-sectional view of the oil pan and sealassembly looking downward from the plane indicated by the line 2--2 ofFIG. 1;

FIG. 3 is a transverse cross-sectional view through one of the fasteneropenings in the plane of the line 3--3 of FIG. 2;

FIG. 4 is a transverse cross-sectional view between fastener openingsfrom the plane of the line 4--4 of FIG. 2;

FIG. 5 is a transverse cross-sectional view of the pan and seal assemblyof FIG. 3 prior to its attachment to the engine frame;

FIG. 6 is a diametral cross-sectional view of a dished isolator washerof the type shown in the assembly of FIG. 3.

FIG. 7 is a cross-sectional view similar to FIG. 3 but showing analternative embodiment of isolation mounting in accordance with theinvention;

FIG. 8 is a transverse cross-sectional view of a reversible sealconfigured for use in the arrangement of FIG. 7; and

FIG. 9 is a diametral cross-sectional view of a flat isolating washerconstruction for use in the arrangement of FIG. 7.

DESCRIPTION

Referring first to FIGS. 1-6 of the drawings in detail, numeral 10generally indicates an internal combustion engine having a frame 11including a generally flat oil pan-supporting lower surface 12 to whichan oil pan 14 is attached by isolation mounting means in accordance withthe invention. The oil pan, as shown, is made of formed sheet steelalthough other materials and methods of forming could be used ifdesired.

The pan 14 is formed as an open topped downwardly closed containerterminating upwardly in an outwardly extending peripheral flange 15. Theflange has generally coplanar inner and outer upper edges 16, 18,respectively, lying along opposite sides of a recessed seal receivingportion 19 that extends the length of the flange. The recessed portion19 receives a peripheral seal 20 and also stiffens the flange againstbending by providing a dished or U-shaped cross section. A plurality offastener receiving openings 22 pierce the flange in the recessed portionat spaced intervals around the periphery. In assembly, the openings 22align with corresponding threaded bores 23 in the frame 11, openingthrough the lower surface 12.

The seal 20 is a continuous resilient vibration absorbing member,preferably molded of silicone rubber, or made in any suitable manner ofany acceptable material. As seen in cross section compressed in FIGS. 3and 4 and uncompressed in FIG. 5, the seal 20 has a flattened top 24connected by sloping sides 26 with a flattened V-like lower portion 27formed to fit within the flange recess 19. Fastener openings 28 extendthrough the seal at locations aligned in assembly with the pan and blockopenings.

At each of the seal openings 28, sleeve-like tubular extensions 30create cylindrical portions extending downwardly from the seal lowerportion 27 protruding, in assembly, through the pan flange openings 22.Enlarged lower edges preferably form sharp edged grommet-like retainers31 slightly larger in diameter than the pan openings 22 and deformableto pass therethrough. In this manner the seal may be retained on the panprior to and during assembly of the pan to the engine frame. Preferably,the seal is additionally provided with tubular inserts 32 molded intothe cylindrical extensions 30 to stiffen the extensions for forcing theminto the pan openings 22.

In assembly, the oil pan 14 is secured to the engine frame lower surface12 by shoulder bolts 34, or equivalent bolt-sleeve assemblies, whichpass through and engage rubber-metal isolator washers 35, holding themin engagement with the lower side of the pan flange 15. The bolts 34also extend through the pan and seal openings 22, 28 and into engagementwith the threaded bores 23 of the frame. The enlarged shoulders 36 ofthe bolts 34 engage the frame surface 12 to limit compression of theseal 20 and isolator washers 35 so as to provide the optimum vibrationisolation of the pan from the frame.

The isolator washers 35, as shown in FIG. 6, are formed from dishedmetal washers 38 molded with a rubber washer 39 between them. Theopenings through the rubber washers 39 and the molded seal 20 are allsmaller than the corresponding openings in the metal washers 38 and thepan flange 15. This is true at least when the rubber portions arecompressed in assembly and is, preferably, also the case prior toassembly as seen in FIGS. 5 and 6. Thus, the contacting metal portionsof the frame 11, bolts 34 and lower washers 38 are positively isolatedby rubber from the pan flange 15 and the upper washers 38 which theflange contacts.

To assemble the oil pan 14 to the frame 11 of the FIG. 1-6 embodiment,the seal 20 is first located in position on the pan flange 15 and thetubular protrusions 30 are forced into the pan openings 22, using aninsertion tool if necessary. Upon insertion, the retainers 31 expand tohold the seal in place on the flange as shown in FIG. 5. The pan andseal assembly is then positioned against the frame surface 12 and thebolts 34 and washers 35 are installed and tightened. The recesses formedat the inner diameters of the dished washers 38 provide clearance forthe seal retainers 31 which extend below the pan flange 15.

Referring now to FIGS. 7-9, there is shown an alternative embodiment ofisolation mounting applied to an engine generally indicated by numeral40. Like reference numerals are used for the illustrated portions of theengine frame 11, oil pan 14 and shoulder bolts 34, since they areunchanged from the first described embodiment. The altered componentsare the resilient vibration absorbing seal 42, shown separately in FIG.8, and the isolator washers 43, shown separately in FIG. 9.

In the resilient seal 42, angled sides 44 connect identical flattenedupper and lower portions 46 having spaced fastener openings 47 extendingtherethrough. Tubular protrusions or sleeve-like cylindrical extensions48 are provided on both the upper and lower portions 46 at each opening47. The extensions are long enough to protrude into, but not through orvery far through the pan flange openings 22.

The seal 42 may be installed with either portion 46 against the panflange, since the fastener receiving hole patterns are symmetrical. Theextensions 48 on the lower portion locate the seal in the pan openings.The shoulder bolts 34 and washers 43 are then installed. Since the sealopenings 47 are made smaller than the shoulders 36 of the bolts 34, thebolts are gripped by the seal, holding all the components in assemblywhile the pan is aligned with the frame 11 and the bolts 34 are threadedinto the bores 23.

The isolator washers 43 are made with flat metal washers 50, since thereis no need to provide clearance for the seal retainers not present inthis embodiment. However, the dished washers 35 of the prior embodimentcould be substituted for the washers 43 if desired.

In assembly, as shown in FIG. 7, the bolts compress the seal 42 anamount controlled by the shoulder bolts but sufficient to flatten theextensions 48 on the upper, frame, side of the seal 42 while theextensions 48 on the lower, flange engaged, side protrude into theflange openings 22. The rubber washers 51 of the isolators 43 are againmade with smaller inner diameters than the metal washers 50 to keep thebolts from grounding against the metal washers 50, thus completelyisolating the pan and frame by rubber members.

While the invention has been described by reference to certainembodiments chosen for purposes of illustration, it should be understoodthat numerous changes could be made without departing from the spiritand scope of the inventive concepts disclosed. Accordingly, it isintended that the invention not be limited to the disclosed embodiments,but that it be given the full scope permitted by the language of thefollowing claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
 1. In an engine having a crankcase with a peripheral wall having a lower edge including a mounting surface and openings through said surface,a downwardly closed oil pan having a peripheral flange extending outward from open upper edges of the pan and mounted in opposed sealing relation to said crankcase wall mounting surface, said flange including openings aligned with the crankcase openings, a resilient vibration absorbing seal compressed between the pan flange and the mounting surface, said seal having openings aligned with the flange and crankcase openings, isolator means below and engaging the flange and having openings therethrough aligned with each of the flange openings, said isolator means including a resilient supporting element, and fasteners extending through said aligned openings and engaging the crankcase wall openings and the isolator means to support the oil pan, said fasteners including an enlarged body portion seated against the crankcase wall adjacent the crankcase openings to limit the compression of said seal and isolator means, said seal including cylindrical portions extending into the flange openings around the fastener body portions to prevent contact between the flange and the fastener means and thereby isolate the oil pan from vibration transmitting engagement with the crankcase and the attached fastener means.
 2. In an engine having a crankcase with a peripheral wall having a lower edge including a mounting surface and openings through said surface,a downwardly closed oil pan having a peripheral flange extending outward from open upper edges of the pan and mounted in opposed sealing relation to said crankcase wall mounting surface, said flange including openings aligned with the crankcase openings, a resilient vibration absorbing seal compressed between the pan flange and the mounting surface, said seal having openings aligned with the flange and crankcase openings, isolator means below and engaging the flange and having openings therethrough aligned with each of the flange openings, said isolator means including a resilient supporting element, and fasteners extending through said aligned openings and engaging the crankcase wall openings and the isolator means to support the oil pan, said fasteners including an enlarged body portion seated against the crankcase wall adjacent the crankcase openings to limit the compression of said seal and isolator means, said seal including cylindrical portions extending into the flange openings around the fastener body portions to prevent contact between the flange and the fastener means and thereby isolate the oil pan from vibration transmitting engagement with the crankcase and the attached fastener means, said cylindrical portions having enlarged lower edges extending below the flange to form grommet-like retainers to secure the seal to the flange prior to assembly of the oil pan to the crankcase.
 3. A combination as in claim 2 wherein the seal openings are sized to grip the fastener body portions and thereby retain the fastener means in assembled position on the oil pan prior to assembly to the crankcase.
 4. A combination as in claim 3 wherein the isolator means comprise sandwich washers having a pair of metal washer elements separated by said resilient supporting elements, the openings through said supporting elements being smaller in diameter than aligned openings in the metal washer elements to prevent contact between the metal elements and the fastener means.
 5. A resilient vibration absorbing seal for isolating and sealing a crankcase and oil pan joint, said seal comprisinga continuous band of vibration absorbing resilient material having generally flattened upper and lower surfaces, a plurality of longitudinally spaced fastener openings extending through the seal upper and lower surfaces, and cylindrical portions extending below said flattened lower surfaces around the fastener openings to prevent contact between the flange of associated oil pan and fastener means and thereby isolate the oil pan from vibration transmitting engagement with an associated crankcase and said fastener means.
 6. A seal as in claim 5 wherein said cylindrical portions have enlarged lower edges extending to form grommet-like retainers to secure the seal to the flange prior to assembly of the oil pan to the crankcase. 